Mayor Bill de Blasio said Thursday that he’s on board with the city’s public high school students skipping class to join a national gun control walkout March 14.

Hizzoner said he’d be a hypocrite if he discouraged the protest barely a week after he introduced new proposals to get young people more involved in voting and more active in local democracy.

“I respect it. If I was a high school student today, I’d be walking out — there’s no question about it,” the mayor said at an unrelated press conference at City Hall. “This is too important a moment in history to try to hold back the desire of our young people to seek fundamental change and to protect themselves.”

The mayor mentioned that typically students would face discipline for ditching class, but that if parents notify a school that their child will participate, it would “mitigate” any punishment.

Neither he nor Department of Education officials could immediately specify what the punishment normally is and whether it would be applied to participants.

The mayor noted there’d be no “lasting impact” on students’ records if they’re disciplined.

Hizzoner noted that the walkout is supposed to be short — lasting 17 minutes, to represent the 17 students and staffers who were killed in last week’s Florida shooting — and that the DOE would ensure it’s done the right way.

In the wake of the massacre, de Blasio also announced new safety measures for public schools — all of which are being required to conduct at least one emergency drill within the next month.

The mayor also said every middle and high school will see unannounced metal-detecting scanners at their entrance — to search students and their belongings for weapons or contraband — at least once in the current school year.

The mobile scanners have been implemented randomly at schools, but until now weren’t required to hit every school in a given year.